The state Supreme Court will decide whether a special prosecutor had authority to investigate Kathleen Kane

PHILADELPHIA — Pennsylvania Attorney General Kathleen Kane and the lawyer who investigated an alleged leak of confidential documents from her office agree that someone has to protect the secrecy of grand jury proceedings.

Their views differ, however, on who has the authority to carry out an investigation into a breach of such secret proceedings, and the extent of that investigatory power.

The subplot to legal arguments made by both sides Wednesday is an investigation launched by a Montgomery County judge that resulted in a grand jury recommendation that Kane be prosecuted for allegedly leaking grand jury secrets.

Kane's lawyer, Joseph A. Del Sole, said judges who oversee grand juries have power to launch investigations into leaks from their own courtrooms.

Del Sole said when Montgomery County Judge William R. Carpenter appointed a lawyer to flush out a suspected leak of information from a case that was before a different grand jury six years ago, he overstepped his authority.

"Judge Carpenter was not protecting the sanctity of the grand jury he was supervising," Del Sole argued.

Thomas Carluccio, the lawyer Carpenter assigned to undertake the investigation, argued that the Supreme Court has said in the past that the power and secrecy of grand jury proceedings call for a "strong judicial hand" and that the appointment of a special prosecutor is appropriate.

He attacked Kane's argument that his appointment by a judge to prosecute her violates the separation of power between the judicial and executive branches of government, arguing that his role was to investigate and present the grand jury's findings to the Montgomery County district attorney.

"I'm not going to be prosecuting anything," Carluccio said.

Arguing that Kane is challenging his authority only to avoid criminal charges, Carluccio added that the time for her to do so was when she learned of his appointment, not after seven months of hearings, including a session when she testified.

"This has been going on for a long time," he said. "When a presentment comes out and the attorney general doesn't like the results of the investigation, then she challenges me."

The arguments were heard by five Pennsylvania Supreme Court justices in a case that could determine whether Kane, a one-time rising star of the Democratic party, faces criminal charges for leaking confidential documents to the Philadelphia Daily News to embarrass a political foe.

Kane has been under scrutiny for nearly a year after the Philadelphia Inquirer revealed that Kane shelved a case launched by former Deputy Attorney General Frank Fina that prosecutors say snared five elected officials taking bribes from an undercover informant posing as a lobbyist.

In June, the Daily News published an article based on documents from the attorney general's office suggesting Fina had failed to investigate allegations that Philadelphia civil rights leader J. Whyatt Mondesire had misused government money.

But even before the article was published, Carpenter, the Montgomery County judge, had started the process of determining how the newspaper obtained the information after Fina and another state prosecutor informed him they had been contacted by a reporter asking about secret material.

The grand jury recommended in December that the Montgomery County district attorney bring charges against Kane for violating the grand jury secrecy act. But after Kane's lawyers persuaded the Supreme Court to hear her challenge, the court barred the filing of any charges until after it makes its decision.

Kane argues that there is no law that allows the appointment of a special prosecutor to investigate the attorney general. Pennsylvania briefly had such a law, but it expired in 2003 and has not been reinstated.

Kane's challenge rests on a 1962 state Supreme Court decision that a Philadelphia judge's appointment of a special prosecutor was unlawful because it violates the constitution's requirement for the judicial and executive branches of government to remain separate.

On Wednesday, Chief Justice Thomas G. Saylor asked whether that was true in Kane's case, noting that Carluccio took the grand jury's recommendation to Montgomery County District Attorney Risa Vetri Ferman, who is an executive branch official, to file charges and prosecute.

Del Sole, a former Superior Court justice, replied that it was unlawful for the judge in Kane's case to allow Carluccio to use the grand jury in his investigation because it is considered an executive law enforcement tool.

Carluccio and Carpenter, who filed a brief but did not appear in court Wednesday, say another state Supreme Court decision gives Carpenter the authority to police grand jury leaks. In that 2008 case, a Dauphin County judge appointed a lawyer to find out how newspapers got information about a grand jury investigation of former Mount Airy Casino owner Louis DeNaples' application for a slot machine license.

The justices peppered Carluccio with questions about the decision.

Justice Debra Todd pointed out that unlike the Dauphin County case, Kane's case involves an alleged leak from a grand jury years in the past. She asked how the Supreme Court's approval of a special prosecutor in an ongoing case permitted investigation of an old case.

"You said the grand jury's secrecy goes on and on," Carluccio replied, adding that the judge who oversaw the 2009 case no longer supervises grand juries.

Justice Correale Stevens asked why the judge couldn't refer the suspected leak to the district attorney. Carluccio replied that in Kane's case, the district attorney had no authority because it was a statewide grand jury.

With both sides drawing on the Dauphin County case for support, Justice Max Baer noted the contrast between Kane's contention that a special prosecutor's powers are strictly limited and Carluccio's assertion that he can do whatever the law allows.

"You're at opposite ends of the football field on this one," Baer said.

The Supreme Court made no rulings Wednesday and does not have a deadline to issue an opinion.